This project involves a study of the Normalized Body Surface Potential Map as an diagnostic tool in cardiology. It encompasses: 1. Construction of a 180 electrode system with dry electrodes and time multiplexing allowing the scan of all electrodes each millisecond. No skin preparation, and minimal time is required for attaching electrode vest. This system is being tested. 2. Investigation of several forms of display of isopotential maps. To date, two-dimensional gray level maps have been studied using the Optronics P-1700 Scanner. 3. Investigation of the normalization for body shape and surface conductivity discontinuity. This involves achievement of a practical device to determine spatial coordinates of the body surface, as well as completion of a study of errors involved in the necessary numerical approximations.